Electric furnace.



J. H. REID.

ELECTRIC FURNACE,

APPLICATION FILED 5130.22, 1908,

Patented Jan. 26, 1909.

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WITH-B8858 ms ATT'YS.

J. H. REID.

ELECTRIC FURNAGE.

APPLIOATION FILED AUG, 22, 1908.

Patented J an. 26. 1909.

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Q. l Eu lL INV'BNTDR WITNESSES FIG... .LHLREID- UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Jan. so, 1909.

Application filed August 22, 1908. Serial No. 449,877.

To all whom it may concern:

Be it known that I, Janus HENRY REID, of Newark, .in the State of New Jersey, United States of America, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a specification.

' My invention relates to improvements in electric furnaces and the general object of my invention is to effect the complete reduction of the ore in a single chamber and so interiorly regulate the passage of the charge that all the ore will be completely treated before it passes out of the furnace.

Further objects are to avoid the necessity of employing a lining for the furnace or if one is employed, to reduce the wear-to a practically negligible quantity, to provide effective means for dpresenting the reducing agent to the ore, an to enable the charge to be subjected at the same time, to the action of the electric arc 'and heat produced through electric resistance, and finally to maintain the electrodes clean and free from the ore.

In carrying out the construction of the invention, a plurality of converging electrodes and resistance elements are employed,

being adapted to form the outlines of a crucible, on which the ore may rest during treatment.

The arc producing electrodes themselves have automatic regulating devices adapted to adjust the position of the electrodes to correspond with the conductivity of the charge, the effect of which is to maintain them in constant movement and to maintain a constant degree of heat in the furnace. The reducing agent for the ore is referably, obtained from the electrodes t emselves, which may be formed of carbon with other suitable compounds accordi to the nature of the ore to be treated, an any slag collecting during reduction, may be raked ofl through suitable doors in the side of the furnace.

All these and other features of the invention are described more fully hereinafter in detail, in the accompanying specifications and drawings.

In the drawings, Figure 1 is a horizontal section through the furnace at the oint at which the electrodes pass through t e walls thereof. Fig. 2 is a vertical'section through a pair of neutral electrodes. Fig. 3 is a vertical section through the arc producin electrodes. Fig. 4 is an enlarged section detail of the regulating device for the aw producing electrodes. Fig. 5 is a detail showing the connection of the current conducting cable to the regulator. Fig. 6 is a sectional detail through the magnetic core of the regulator. F 7 is a sectional detail on the line 22, i 4

1n the drawings, likedettels of reference indicate corresponding parts in each figure.

Referring to the drawings, A represents the bod portion of the furnace of suitable materia provided with a hop or 10 for introducing material at the top t ereof, and a discharge outlet 11 in the bottom.

. In the embodiment illustrated, no lining is illustrated in the furnace, as owing to the manner of supporting the ore on the electrodes, which ractically constitutes a crucible therefor, t is is not absolutely necessary. It is evident, however, that if desired, a lining of suitable heat-resisting material might be employed, instead of the metallic casing illustrated.

B and G represent the are producing electrodes and F, E, G, H and I represent a plurality of resistance elements, similar in form to the electrodes, all the resistance elements and the electrodes converging to a single point within the furnace, whereby a cruel le will be formed on which the charge will be retained until it is reduced and brought to a molten state, when the molten elements may drop between the resistance elements and the electrodes.

In using the furnace, the aim will be to bring all the metals to a reduced and molten state when they may flow past the electrodes, and any slag rising to the top of the ore during the reduction process ma be raked off through suitable doors J. If esired, certain of the metals having a low vaporizing point may be vaporized and withdrawn through a suitable outlet pipe 35, as hereinafter described.

B and C are the arc-producing electrodes, which are convergingly and downwardly inclined towards the center of the furnace, and are slidably supported on the exterior in brackets 12 and 13. Each of these electrodes has a regulating device D adapted to bring the electrodes together, and separate them to correspond with the conductivity of the charge, whereby the current assing through, may remain constant. these regulators, as shown in detail in Figs. 4, 5 and 6 is famed with helical resistance ach of coils 14 constituting electromagnets and supported by a suitable bracket 15 connected to the bracket 12 or 13, the said resistance coils being placed in the electric circuit by means of a cable 16 connected to the lower end and a cable 17 on the upper end extending from the coil to a binding ost 18 on the electrodes, suitable electrica insulation being provided between the coil and supporting racket.

Adjustable within the helical coil is the laminated core 19 formed of cross-shaped sheets 20 of soft iron, assembled on a central rod 22, and having corners 21 of insulating material, such as marble or porcelain, and by means of which the conducting part of the core may be maintained out of contact with the wear of the helical resistance 14.

The movement of the core within the magnet is communicated to the electrode through the medium of a lever 23, connected at one end to the electrode and pivoted at 24 to a projection 25 from the bracket 15, and hav- 1ng a stirrup 26 pivotally connected to the same, beyond the bracket, the said stirrup extending along both ides of the core and being adjustably connected to the central rod 22 thereof, by means of suitable bolts 27. These bolts enable the core to be adjusted and this, as will hereinafter appear, will vary the amount of the current which will pass through the electrodes. The core is normally maintained in outermost osition, and its inward motion is resisted y a tension spring 28 connecting the outer end of the lever 23 and with a plate 29 supported from the outer end of the coil 14, but insulated therefrom.

It will be seen that when the current passes through the coil, it tends to draw the core inwardly, and this is resisted by the spring 28. The core will then assume a osi'tion resu ting from the balance of the pu l on the magnet and the spring. Should the conductivity of the char e increase and an excessive current be passe throu h the electrodes, it will pull the core inwardfy further, and this, through the medium of the lever 23, will withdraw the electrode and thus reduce the amount of current passing through. As the conductivity of the charge is constantly varying this action will maintain the electrode in constant movement cleaning the surface thereof and preventing the ore sticking to the same.

The resistance elements E and F, as well as constituting part of the crucible, are adapted to afford an electric heat-producing resistance, and they extendthrough brackets 30 and 31, in the side of the furnace, converge downwardly, and meet between the arcroducing electrodes B and C, the ends of the said resistance elements being held constantly in contact through the medium of springs 32 and 33 connectin the bracket 30 or 31 with rings 34 on the electrode. As

these resistance elements meet between the point of the are producing electrodes, arcs will be created at the contacting side of the resistance elements and the arc-producin electrodes, and the current passing throng the end of the resistance elements will heat the same, thereby producing an electric resistance between the extremities of the arcproducing electrodes and the charge will thus e subjected to both the action of the electric arc and the heat of the electric resistance. To complete the crucible for the charge'and also to increase the amount of electrical resistance within the furnace, a plurality of smaller resistance elements G, H and I may be provided between each of the larger resistance elements E and F, and the arcroducing electrodes D and C. These smal resistance elements G, H and I are similar in form to the elements E and. F, and are sup ported. in a similar manner, being held in c'ontact with the larger elements by gravity, which causes them to slide downwardly towards a converging central point.

The electrodes and resistance elements, as shown in the drawings, all converge to a central point and in order that these points may be 0 the maximum strength to en port the charge, the under surfaces of the e ectrodes and resistance elements are made V-sha ed. in form, as appears in Fig. 1. The num er of electrodes and resistance elements employed and convergin in this manner, form substantially a crucib e in the center of the furnace, and the charge introduced into the furnace rests on this and before it can pass through the electrodes and resistanceelements it must be reduced to at least a molten form which will enable it to slip through the small spaces between the electrodes. Thus it is always insured that the ore has received the pro er amount of treatment before it asses t rough the furnace. Any slag may e withdrawn through the door J and, 1f necessary, the volatile products may be withdrawn throu h the outlet 35.

In place 0 introducing an external reduc ing agent I pro ose to use the electrodes, or the resistance e ements, to supply the reducing agent to the ore, and the carbon of the electrodes or resistance elementsmay, have a suitable reagent such as lime incorporated with it. The volatile or gaseous products resulting from the reduction of the ore may be withdrawn, through a suitable outlet pipe 35, preferably located below the electrodes.

It will be observed that owing to the manner of sup orting the charge from the electrodes, and out of contact with the walls, it is not necessary to em loy any lining'in the furnace, and further t e employment of the neutral electrodes makes a combined resistance and are furnace. The volatile products are preferably exhausted through the pipe by suitable vacuum producing means, and

i the abstraction of the hot thc current and being introduced throug this, as well as exhausting the said products, will tend to maintain the chamber cool by ases. I It'will be, observed that t e furnace I have herein described enables a very complete treatment to be given to the ore. In the first place, the ore is subjected to both the electric arc and t e resistance heat, andthc amount of each of thgse can be adjusted and varied in order to produce the exact temperatm. and character of heat necessary to most e ectually reduce the frcduction. The guantity of t e reducing agent intro iucee in the ore may also be regulated b theelectrodes is always uniform in character. The metals obtained by the reduction ma be either volatilized and withdrawn through the outlet Lor brought to amolten state arid allowed to pass throu and drop out the bottom 0 the furnace. certain cases it may not be necessary to withdraw any of the volatile products and in this case, the electrodes would be more or less closely togetherin order to moreffec;

tually constitutethe crucible for supporting the charge even when said charge IS in a partially molten state.

As many changes could be made in! the above construction 'and many apparently widely different embodiments of my inventhe spirit or scope thereof, it is intended that allmatter contained in these s ecifications and drawings shall be interprete 'as illustrative and not in a limiting sense. It is also to be understood that the language of the'following claims is intended to cover such h the electrodes In generic and 'ecific feats-fies cf the gn'enticn herein descri ed, which, as a matter of langua e, might be said'to be included thereby.

t I claim as my invention is 1'. In-an electric furnace, with a air of are producing electrodes and a pair 0 neutral resistance elements having contacting ends extending between the ends of the are producing electrodes, andmeans for maintaining the resistance elements in contact Witheach other.

2. In an electric furnace, the combination the combination with a pair of are producing electrodes, and

automatic constant current regulators for the same, of a pair of neutral resistance elements having contacting ends extending between the ends of the are producing electrodes.

3. In an electric furnace, the combination witha pair of are producing electrodes, of a plurality of converging resistance elements etween the are producing electrodes adapted to at once constitute a crucible to support the charge and aii'ord electric resistance to the passage of the current.

4. In an electri furnace, the combination with a plurality o arc-producing electrodes, of a plurality of resistance elements extending intothe are produced thereby, adapted with ".tlie .electrodes,-to form a crucible on which the charge may rest during treatment. tron could be made without departing from JA MES HENRY REID.

i jWitnessest l i RUsjsEL S. SMART, y fi st. A. WYMAN. 

